Multi-scene recording medium and apparatus for reproducing data therefrom

ABSTRACT

A multi-scene recording disk and a data reproducing apparatus, which enables a user to select and enjoy one of simultaneously proceeding scenes, and also enables a program editor to edit programs using a new concept and novel fashion. Related program movements, each consisting of program bars, are recorded on the disk 100. The data reproducing apparatus includes a data string processing section 203, a system control section 204, an operator panel 205, a video processing section 206, and audio processing sections 211 and 213. The sections 203 and 204 and the panel 205 select any one of the program movements and switch one movement to another, and select any one of the program bars of the movement selected and switch one bar to another. The information thus selected is supplied to the video processing section 206 and the audio processing sections 211 and 213.

This is a division of application Ser. No. 08/454,289, filed Jun. 15,1995 which was based on International Application No. PCT/JP93/01570filed Oct. 29, 1993 which designated the U.S.

TECHNICAL FIELD

The present invention relates to a multi-scene recording medium, such asan optical disk or a CD-ROM, for recording a program such as a movie,and also to an apparatus for reproducing any one of the data strings ofthe program, which represent independently proceeding scenes of a movie.

BACKGROUND ART

Conventional movies are formed from a time-series of scenes. Theycontain no scenes which proceed simultaneously. Hence, the audience seesonly one scene at a time on the screen. The audience cannot enjoy seeinganother scene which can proceed along with the scene they are actuallyseeing. For example, the audience cannot see a scene of the cockpit of aspace shuttle and a scene of the ground control center at the same time,though these scenes are proceeding simultaneously. This is because thesescenes have been connected together forming a time series of sceneswhich is generally known as a movie film. Another example may be anopera movie. Some of the audience may wish to see only the scene of theentire orchestra for some time, some others may want to watch thezoom-up face of a leading opera singer-player, and still some others maylike to look into the conductor's zoom-up face. In other words, peoplein the movie theater may wish to, but cannot, see different scenes atdifferent timing. With television broadcasting, it is possible topresent two scenes of the same program at the same time on amulti-screen. For instance, a moving picture of an object, photographedat a long distance, and a moving zoom-up picture of the same object canbe transmitted on two channels, respectively. Therefore, the TV watchercan select whichever picture he or she wants to see on the TV screen atany timing he or she wants.

However, the program data recorded on a recording medium is nothing buta time-series of scenes, and the user cannot see any other scene thanthe very scene being reproduced from the medium. In other words, he orshe is unable to select one of the simultaneously proceeding scenes.Although movie film editors can combine two simultaneously proceedingscenes, forming a times series of scenes, the user can have but alimited freedom of selecting scenes.

With television broadcasting technology it is possible to transmits twoor more simultaneously proceeding scenes through a plurality ofchannels. The program data recorded on a recording medium represents atime series of scenes, and the user has no freedom of selecting any oneof simultaneously proceeding scenes.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide amulti-scene recording medium recording a program representingsimultaneously proceeding scenes, and also an apparatus which enables auser to select any one of the simultaneously proceeding scenes.

Another object of the invention is to provide a multi-scene recordingmedium recording a program representing simultaneously proceedingscenes, and also an apparatus which enables a user to switch thesimultaneously proceeding scenes, from one to another.

Still another object of the invention is to provide a multi-scenerecording medium recording a program representing simultaneouslyproceeding scenes, and also an apparatus which enables only anauthorized user to select specified ones of the simultaneouslyproceeding scenes.

A further object of this invention is to provide a multi-scene recordingmedium recording a program representing simultaneously proceedingscenes, and also an apparatus which can easily reproduce from therecording medium any one of the simultaneously proceeding scenes which auser wishes to enjoy.

The multi-scene recording medium according to the present invention hasa management area and a data area. In the data area, there is recordedprogram information which comprises a first program movement containinga plurality of first program bars and a second program movementcontaining a plurality of second program bars. In the management area,there is recorded multi-scene configuration information representing theexistence of the first and second program movements.

The data reproducing apparatus comprises scene selecting means forreading the multi-scene configuration information from the managementarea of the recording medium for reproducing the first program movementor the second program movement from the data area of the recordingmedium in accordance with the multi-scene configuration information.

Provided with the scene selecting means, the data reproducing apparatusgives a user the freedom of selecting one of simultaneously proceedingscenes, and enables a program editor to edit programs in new concept.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a data reproducing apparatus accordingto an embodiment of the present invention;

FIG. 2A is a diagram illustrating the recording regions of a diskaccording to this invention, and FIG. 2B is a diagram representing thedata format of the disk shown in FIG. 2A;

FIGS. 3A and 3B are diagrams showing examples of data strings recordedon the disk shown in FIG. 2A;

FIGS. 4A to 4C are diagrams showing three different menus, respectively,which the apparatus of FIG. 1 displayed;

FIGS. 5A to 5C are diagrams showing other menus which the apparatusdisplays;

FIG. 6 is a diagram for explaining how the menus can be switched, fromone to another, by operating the data reproducing apparatus;

FIG. 7 is a diagram representing a menu displayed by the datareproducing apparatus;

FIGS. 8A to 8C are diagrams illustrating the data tables recorded in themanagement area of the disk;

FIG. 9A shows another example of data string recorded on the disk, andFIGS. 9B to 9D are diagram illustrating information tables recorded onthe disk;

FIGS. 10A and 10B are diagrams showing another example of a menupresented by the data reproducing apparatus;

FIG. 11 is a flow chart for explaining an operation of the datareproducing apparatus;

FIG. 12 is also a flow chart for explaining an operation of the datareproducing apparatus;

FIG. 13 is a diagram explaining how the data reproducing apparatusswitches scenes;

FIG. 14 is a diagram also explaining how the data reproducing apparatusswitches scenes;

FIG. 15 is a flow chart for explaining an operation of the datareproducing apparatus;

FIG. 16 is another flow chart for explaining an operation of the datareproducing apparatus;

FIG. 17 is still another flow chart for explaining an operation of thedata reproducing apparatus;

FIG. 18A is a diagram showing an image which the data producingapparatus has reproduced, and FIG. 18B is a diagram illustrating anexample of a data string recorded on the disk;

FIG. 19 is a flow chart for explaining an operation of the datareproducing apparatus;

FIGS. 20A to 20C are diagrams showing examples of messages reproduced bythe data reproducing apparatus;

FIG. 21A is a diagram illustrating another example of a data string, andFIG. 21B is a diagram showing part of the data reproducing apparatuswhich serves to process the data string; and

FIG. 22A shows another example of a data string recorded on the disk,and FIG. 22B is a flow chart for explaining how the data string isprocessed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings.

As shown in FIG. 1, a recording medium such as an optical disk 100(hereinafter referred to as "disk") according to the present inventionis installed in a data recording/reproducing apparatus (accessapparatus).

The disk 100 is placed on a turntable 101 which is rotated by a motor102. In the reproducing mode, the information recorded on the disk 100is read by pickup means 103. A pickup driving section 104 providesmovement and tracking control of the pickup means 103. The output of thepickup means 103 is supplied to a modulation/demodulation section 201,which demodulates the signal into demodulated data. The data is suppliedto an error correcting data processing section 202, which correctserrors and supplies the resultant signal to a data string processingsection 203. The section 203 extracts video information, subtitle andcharacter information, and audio information from the signal. As will beexplained later, the subtitle and character information and audioinformation are recorded on the disk 100 in correspondence with thevideo information. Various languages can therefore be selected for thesubtitle and character information and audio information. The selectionis made under the control of a system control section 204. The usersupplies the input from an operator panel 205 to the system controlsection 204.

Information, e.g., movie information, is recorded on the disk 100. Morespecifically, a plurality of simultaneously proceeding scenes arerecorded on the disk 100, one of which can be selected by a user and cansubsequently be reproduced. To enable the user to select one of thescenes and have it reproduced, the data string processing section 203,the system control section 204 and the operation section 205 constitutea data string control means and a scene selecting means.

The video information is separated at the data string processing section203 and supplied to a video processing section 206. The section 206decodes the data string in accordance with the type of the display unitused. For example, the section 203 converts the video information into asuitable form for an NTSC, PAL, SECAM, or wide screen. The video signalobtained by decoding the video information is supplied to an adder 208.The adder 208 adds the signal to the subtitle and character information.The resultant sum is supplied to an output terminal 209. Meanwhile, theaudio information separated at the data string processing section 203 issupplied to an audio processing section 211. The section 211 demodulatesthe audio information into a demodulated signal, which is supplied to anoutput terminal 212.

The audio processing section 211 and another audio processing section213 constitute an audio unit which works as a decoding section. Theaudio processing section 213 can reproduce speech in another language,which is supplied to an output terminal 214. (This function will bedescribed later.)

The apparatus can record information on the disk 100. In the recordmode, a video signal to be recorded is supplied to an input terminal301, and an audio signal to be recorded is supplied to an input terminal302. The video processing section 206 acts as a video encoder, whereasthe audio processing section 211 as an audio encoder. The data stringprocessing section 203 works as a formatter for recording information,and the error correcting data processing section 202 functions as anerror code adding section. The data, thus processed, is modulated by themodulation section 201 and sent to the pickup means 103 as data to berecorded.

As described above, the disk 100 stores a plurality of program dataitems (multi-scene program data) which are related to one another.Therefore, the data reproducing apparatus can reproduce any of theprogram data items that the user has designated, and can stopreproducing one program data item and immediately start reproducinganother program data item.

Also recorded on the disk 100 are: audio data including speed data invarious languages, music data and sound effect data; and visual datasuch as subtitle data in various languages. One or more of these varioustypes of data are selected and reproduced by the data string controlmeans and scene selecting means constituted by the data stringprocessing section 203, the system control section 204 and the operatorpanel 205.

The disk used in the invention, its recording format, and itsapplication will be described.

A movie may be recorded on the disk used in the invention. In this case,the disk stores the data representing a plurality of simultaneouslyproceeding scenes, a plurality of language data items, and a pluralityof subtitle data items in various languages.

FIG. 2A shows the data area of the disk 10. A management data area isprovided at the center of the disk 10, and the data area surrounds themanagement data area. Recorded in the management area is management datafor managing the programs recorded in the data area, as will beexplained later. The programs recorded in the data area includesubcodes, subpicture, audio information, and video information.

The kinds of information items recorded in the data area will bedescribed, with reference to FIG. 2B.

FIG. 2B is an enlarged view of the contents of data unit DUT #0 in thedata area. In data unit DUT #0, there is a subcode (SUB-CODE) at thestart, followed by a subpicture information (SUB-PICTURE), audioinformation (AUDIO), video information (VIDEO) in the order they arementioned. The subcode (SUB-CODE) contains the attributes of data unitDUT #0, such as the amount size of the data unit, the start positions ofthe video information and audio information included in the data unit,and control information for the data unit. Each subpicture (SUB-PICTURE)contains, for example, subtitle information (for movie video) orcharacter information (for Kara-OK video and educational video). Thesubtitle information and the character information are comprised ofeight pictures PICTUREs #0 TO #7 each. All of these PICTURES differ inlanguage (or some of them differ in language) and the remaining onescontain no signals. Furthermore, other items of information, whichdiffer in purpose, such as those representing questions and answers, maybe recorded on the disk 100. The audio (AUDIO) information is recordedin the form of music information or speech information, which consistsof at most eight information items AUDIOs #0 to #7. (Each of the eightaudio information items last about one second when reproduced.) Theaudio (AUDIO) information can be used in various fashions; it may bereproduced in the form of a combination of orchestra and solo-singing ora combination of Kara-OK and vocal performance. The audio information isrecorded in units of frames, each frame #0, #1, . . . comprising aheader (HEADER) and data (DATA). The video (VIDEO) information consistsof, for example, 30 frames of images. (When reproduced, the informationlasts about one second.) The video (VIDEO) information is recorded byhigh-efficient coded image compression technique. The number of framesis not limited by standard. The audio information has been subjected tohigh-effect encoding.

The types of data units DUTs will be described.

FIG. 3A illustrates an example of program data.

Hereinafter, a program forming one stream shall be called "programmovement," and a plurality of program forming the program movement shallbe called "program bars." Each of the program bars is composed of aplurality of data units which have been explained with reference to FIG.2.

The program data shown in FIG. 3A consists of two program movements 901and 902. The first program movement 901 represents a scene showing anentire orchestra, photographed by a first camera, and the second programmovement 902 represents a scene showing a zoom-up picture of theconductor only, photographed by a second camera. Either the firstprogram movement or the second program movement can be reproduced fromthe disk 100 by means of a monitor, so that a user may listen to themusic and watch a moving picture of the selected program movement.Further, as is indicated by the broken line in FIG. 3A, the user canenjoy the picture and sound of the second program movement, whilelistening to the music of the second program movement 901 and seeing thepicture thereof, reproduced and displayed on the monitor. That is, theuser has freedom of selecting a scene. A program consisting of moreprogram movements than the program shown in FIG. 3A may be recorded onthe disk. The program movements of such a program may representsimultaneous proceeding scenes tracking brothers who grew in the samehouse and then started different walks of life.

FIG. 3B shows an example of a program data with which it is possible tooutput scenes which proceed simultaneously with part of the standardprogram movement 903. This program data can be smaller in amount thanthe program data of FIG. 3A. Of the program bars constituting thisprogram data, the bars #1 and #2 form a multi-scene, and the bars #4, #5and #6 form another multi-scene. The program data can be edited suchthat the standard program movement 903 is one photographed by a camera0, the program bars #2 and #5 are those photographed by a camera 2, andthe program bar #6 is one photographed by a camera 3.

Let us assume that the standard program movement 903 represents, forexample, a time-series of baseball game scenes photographed by thecamera 1 located right behind the home plate, that the program bars #2and #5 represent two baseball game scenes photographed by the camera 2installed in the outfield, and that the program bar #6 represents abaseball game scene photographed by the camera 3 set in the right stand.Then, when this program data is reproduced, the program bar #0 isreproduced first, and a menu is displayed immediately after the lastframe of the program bar #0 has been reproduced. Thus, the user canselect any one of the following scenes.

FIG. 4A shows an example of a menu which gives the user the opportunityto select any scene he or she wishes to see. The menu reads,"MULTI-SCENE MODE STARTS FROM HERE. SELECT SCENE #1 OR #2." Atcompletion of the reproduction of the program bar #3, another menu isdisplayed which reads, as shown in FIG. 4B. "MULTI-SCENE MODE STARTSFROM HERE. SELECT SCENE #4, #5 OR #6." The menu may be displayed inanother form. For example, as shown in FIG. 4C, it may read:

"MULTI-SCENE MODE STARTS FROM HERE

#4: BACK-NET ANGLE

#5: CENTER-FIELDER ANGLE

#6: FIRST-BASE ANGLE"

The user operates the operator panel 205, thereby selecting one of theprogram bars. The data reproducing apparatus reproduces the program barselected.

As mentioned above. the menu shown in FIG. 4A, FIG. 4B or FIG. 4C isdisplayed at completion of the reproduction of any program bar.

Instead, other types of menus may be displayed. For example, as shown inFIG. 5A, representative scenes or heat scenes of the program bars #4, #5and #6 are simultaneously read from the disk and displayed.Alternatively, as shown in FIG. 5B, the scene of the standard programmovement 903 is displayed in a large size, whereas the representativescenes of the program bars #5 and #6 are displayed in a small size. Thisalso gives the user freedom of selecting scenes.

Also, as shown in FIG. 5C, only the key data of the program bars #5 and#6 may be displayed, for example, in the order of the screen, while thescene of the program bar #4 of the standard program movement 903 isdisplayed, thereby indicating that there are program bars #5 and #6which correspond to the program bar #4.

Furthermore, as shown in FIG. 6, the representative scenes of theprogram bars #4, #5 and #6 may be repeated and cyclically displayed, oneafter another, each scene for a period of, for example, two seconds. Inthis case, the user selects the desired program bar by operating theoperator panel while the representative scene of the desired program baris being displayed.

In the instances described above, while the standard program movement903 is being reproduced, a menu is displayed to inform the user that aprogram bar other than those of the program movement 903 is recorded onthe disk, constituting a multi-scene. According to the presentinvention, the user can designate and set an order in which program barsshould be reproduced.

FIG. 7 shows an example of a menu which is displayed when the disk isinserted into the data reproducing apparatus. The data reproducingapparatus reads the management data from the disk 100, and determinesthat there are two or more program bars recorded representingsimultaneously proceeding scenes. Then, the apparatus causes the monitorto display the menu. Seeing the menu, the user operates the operatorpanel 205 to select from among, thereby selecting the image photographedby the camera #0, the image photographed by the camera #2, or the imagephotographed by the camera #3. If the key data corresponding to thecamera #0 is selected, the apparatus is set to reproduce the programbars of the data string 904 shown in FIG. 3B. If the key datacorresponding to the camera #2 is selected, the apparatus is set toreproduce the program bars of the data string 905 shown in FIG. 3B. Ifthe key data corresponding to the camera #3 is selected, the apparatusis set to reproduce the program bars of the data string 906 shown inFIG. 3B.

The management data recorded in the management area of the disk 100 willbe explained first. This data is provided in the form of a managementtable.

As shown in FIG. 2, the management table consists of a volume identityfield (VID), a picture information field (PIF), and a data unitallocation table (DAT). The the VID is the innermost annular field ofdisk 100. The PIF is the second innermost annular field surrounding theVID. The DAT is the third innermost annular field.

The VID is a 256-byte field, the first byte of which is the first bytein the management area. The VID represents various items of informationabout the disk 100, among which are items showing the countries wherethe recorded languages are used.

As shown in FIG. 8A, when there are program movements and bars whichconstitute a multi-scene, information regarding how those program barsare combined is recorded in table form. FIG. A8 shows the combinedinformation on the program shown in FIG. 3B.

The link of the program bars is defined by the PIF. FIG. 8B shows thePIF used for controlling the program data illustrated in FIG. 3B. Thenumber (e.g., the first address) of the current and subsequent programbar to be reproduced is defined in the PIF. As can be understood fromFIG. 8B, the program bar #1 will be reproduced after the program bar #0has been reproduced, the program bar #3 will then be reproducedimmediately after the program bar #1 has been reproduced, and so forth.The fact that the program bars #1 and #2 represent two simultaneouslyproceeding scenes is recognized not from the PIF, but from the VID. Thecontrol software has been prepared so as to display a menu, giving theuser a chance to select program bar #1 or #2 after the completion of thereproduction of the program bar #0. Namely, the data reproducingapparatus does not immediately start reproducing the program bar #1immediately after reproducing the program bar #0. Rather, it waits untilthe user inputs bar-selecting data. If the user selects the program bar#2, the data reproducing apparatus begins to reproduce the program bar#3 after the reproduction of the program bar #2, in accordance with theprogram link which is recorded in the PIF.

After reproducing the program bar #3, the data reproducing apparatuswaits for any instruction made by the user. This is because the programbar #4, which is to be reproduced after the program bar #2 (as definedby the program link recorded in the PIF), represents a scene whichproceeds simultaneously with those represented the program bars #5 and#6. After reproducing the program bar #4, #5, or #6, the datareproducing apparatus starts reproducing the program bar #7, as definedby the program link recorded in the PIF.

Recorded in the PIF is information on various elements of each program.For example, 16 bytes are used for each program bar. The informationincludes the start and end time of the program bar, no matter whetherthe program bar is for home video, movie, Kara-OK, computer graphics,interactive use, game or computer data. The identification of a speechencoding system, the identification of an image encoding system, and thepicture attributes (i.e., the information identifying the aspect ratioand a system such as PAL or NTSC system, and information on horizontalresolution and vertical resolution). It also includes a start pointerhaving a value indicating the DAT address at which the data at the startpoint of a program bar is recorded.

In the DAT, the information indicating the order in which the programbars of a program are to be read from the data area of the disk 100,after the program bar been selected and identified.

The DAT contains parameters such as a zone number (NZON), a sectornumber (NSCT), a track number (NTRC), a program time (PTMB), and a lingpointer (PNTL). From the zone number (NZON), the track number (NTRC) andthe sector number (NSTC), the sector at the start of the data unit canbe determined. The NZON is the zone number to which the sector at thestart of the data unit belongs. The zone number is assigned to a unit ofa plurality of tracks, separated from any other unit in the radialdirection of the disk; zone number 0 is assigned to the innermost unitof tracks. The NSTC indicates the number of the sector at the start ofthe data unit recorded in a track. The sector number is a numbercomplete in the zone. The NTRC indicates a track number in the zone. ThePTMB is a flag representing the time position of the image data (i.e., Ipicture) at the start of the data unit. The time position is the time(in seconds) elapsed from the program starting point. The time positionis used in searching for time codes. Furthermore, the time position isinput into the data reproducing apparatus. The apparatus uses the timeposition as the start reference data in order to display the programtime, the absolute time, the remaining time of the program, and thelike. The PNTL is a flag showing the data unit number immediatelyfollowing the present data unit number in time. The unit for this flagcorresponds to the number of the data unit. When there is no linkdesignation at the end of the program, all bits are set at "1"(=0×FFFF). The effective value for the link point ranges from 0×0000 to0×FFFF.

FIG. 8C illustrates part of the DAT. Assume the program bars #0 and #1,both shown in FIG. 3B, last 3 minutes 40 seconds and 1 minute and 18seconds, respectively. Then, as shown in FIG. 8C, the lasting time of 1minute and 18 seconds is set for the program bar #2 which is linked tothe program bar #1 as shown in FIG. 3B. Thus, if the standard programmovement 903 represents a series of scenes showing an orchestra playingmusic, which has been photographed by a camera located at a position,then it is possible for the user to select and see another scene of theorchestra, photo-graphed by a camera located at a different position. Asshown in FIG. 8C, the DAT contains a zone number (NZON), a sector number(NSTC), a track number (NTRC), and a link pointer (PNTL). It is theprogram time (PTMB) which corresponds to the time for which each dataunit last. In other words, the PTMB indicates the period for which eachof the data units forming any the program bar reproduced from the disk100.

Once a program to be reproduced has been determined, the system controlsection 204 controls the pickup driving section 104. Under the controlof the section 204, the section 104 moves the pickup means 103 to thatportion of the disk 100 where the desired program is recorded. Thus, theapparatus reproduces the desired program from the disk 100 in accordancewith the management data read from the management area of the disk 100and the selection data input by the user.

In the program illustrated in FIG. 3B, the program bars which are linkedto one another will last for the same period of time they have beenreproduced. For example, as has been described, the program bars #1 and#2 will last for the same time of 1 minute and 18 seconds when they arereproduced.

A program, which does not include audio information representing a pieceof music continuously lasting for some time, may be recorded on the disk100 in a form different from the program illustrated in FIG. 3B. FIG. 9Ashows the format of such a program. This is a movie program consistingof three program movements representing three stories 1, 2 and 3. Morespecifically, the program bars #0, #1, #5 and #6 represent the story 1about a first hero; the program bars #0, #2 #3 and #6 represent thestory 2 about a second hero; and the program bar #0, #1, #4 and #6represents the story 3 of the third hero. In the case of a multi-scenestory like this, the program bar #1 need not last for the same time asthe program bars #2 and #3, when reproduced. When a program of this typeis recorded on the data area of the disk, the picture information field(PIF) recorded in the management area of the disk contains a pluralityof program link tables of the types. The table shown in FIG. 9B is astandard PIF table which is used when the user selects the story #1. Thetable of FIG. 9C is a standard PIF table which is used when the userselects the story #2. The table of FIG. 9D is a standard PIF table whichis used when the user selects the story #3.

The various types of the multi-scene movie programs thus far describedcan be reproduced from the disk in such a way that the user can selectand enjoy any one of the simultaneous proceeding scenes or stories.

According to the present invention, it is possible to record amulti-scene movie program such that specified ones of the scenes orstories cannot be selected or enjoyed by those who are not authorized inaccordance with laws or in only some countries.

The specified scenes or stories cannot be selected or enjoyed in somecountries, because they are prohibited from being displayed in thosecountries.

More specifically, the sub-code (SUB-CODE) of the data unit DUTrepresenting, for example, the story #3 may contain a parental consentcode or a country code, or both, thus prohibiting the story #3 of themovie program. In this case, when the user selects story #3, the datareproducing apparatus reads the program bar #4 from the disk 100, butwill replace or mask the scene represented the program bar #4, eitherentirely or partly, with a totally different image. The parental consentcode authorizes only the parents to have access to to the scenes orstories to which this code is added. The country code is contained inthe sub-code (SUB-CODE) of the data unit DUT recorded on a disk 100 soldin a country where the specified scenes or stories should not bedisplayed. Either type of a code is recognized in the data reproducingapparatus.

The video information representing the different image which willreplace or mask the scene represented by the program bar, eitherentirely or partly, is recorded on the disk. Also, management datashowing the address of this video information is contained in thestandard PIF table which is used when the user selects a story.Alternatively, the data reproducing apparatus may incorporate a devicefor generating signals for jamming or masking the scene represented bythe program bar selected.

When a country code is used, it defines a combination of scenes, i.e., acombination of program bars. If a country code for Country A iscontained in the sub-code (SUB-CODE) recorded on the disk to be sold inCountry A where the scene represented by the program bar #4 must not bedisplayed, the country code defines the combination of scenes #0, #2, #5and #6. If a country code for Country B is contained in the subcode(SUB-CODE) recorded on the disk to be sold in Country B where the scenerepresented by the program bar #5 must not be displayed, the countrycode defines the combination of scenes #0, #1, #4 and #6. Thecombination of scenes, thus defined, can be displayed on the monitor asthe data reproducing apparatus reproduces the corresponding program barsfrom the disk. Any country code contained in the sub-code (SUB-CODE) iscompared with the various country codes stored in the data reproducingapparatus. If it is identical with none of the country codes stored inthe apparatus, the apparatus will not reproduce the correspondingprogram bar.

FIG. 10A is a diagram showing a scene which is masked in part. FIG. 10Bis a diagram illustrating a scene replaced by an image, such as amessage telling the user that the program being reproduced in parentalconsent mode and that the user needs to input the secret code in orderto release the parental consent mode.

It will now be described how to switch simultaneously proceeding scenes,from one to another.

FIG. 11 is a flow chart explaining how the data reproducing apparatusoperates to give the user a chance to select one of the simultaneouslyproceeding scenes represented by the program bars recorded on the disk11. It is determined whether or not the end of any program bar is beingreproduced (Step Si). If the end of any program is being produced, it isdetermined whether or not any program bar is linked to the next programbar (Step S2). This is possible by storing the management data into awork memory incorporated in the data producing apparatus. If such aprogram bar is linked to the next program par, the next program barlinked to the first one is reproduced from the disk (Step S3). If such aprogram bar is not linked to the next program bar, it is determinedwhether or not any data has been input which indicates that any programbar has already been selected (Step S4). The data, if any, has beeninput by operating the operator panel before the program is reproducedand has been stored in the memory incorporated in the system controlsection, as shown in FIG. 7. If such data has been input, the selectedprogram bar is reproduced from the disk (Step S5). If such data has notbeen input, a menu of the type shown in FIG. 4A, 4B, 4C, 5A, 5B, 5C or 6is displayed on the monitor, giving the user a chance to select one ofthe candidate program bars (Step S6). Then, it is determined whether ornot the user has input data designating his or her choice using theoperator panel, (Step S7). If the user has input this data, the programbar selected is reproduced (Step S8). If the user has not input suchdata, Step S6 is performed again. If no data is input from the operatorpanel for a predetermined time, the program bar of the standard programmovement will be automatically selected, reproduced from the disk, anddisplayed on the monitor.

FIG. 12 is a flow chart for explaining how the data reproducingapparatus operates when the user input the data designating a desiredscene for viewing, at any time while the first program bar is beingreproduced from the disk. In this case, program bars representingsimultaneously proceeding scenes can be switched, from one to another,without break.

While the first program bar is being reproduced, it is determinedwhether or not data designating any selected one of simultaneouslyproceeding scenes has been input (Steps S11 and S12). If the data hasbeen input, it is determined whether or not any second program bar islinked to the first program bar, by referring to the volume identityfield (VID) of the management table (Step S13). If the second bar islinked to the first program bar, the number of the first data unitcontained in the first program bar, and the number (FNO) of the framesof the first program bar which have already been reproduced are storedinto a memory (Step S14). Further, the time (TL1) for which the firstdata unit will last when reproduced is input also into the memory (StepS15). The time (TL1) can be obtained from the data unit allocation table(DAT), as has been explained with reference to FIG. 8C. Then, the startaddress of the second program bar to be reproduced is identified byreferring to the picture information field (PIF), and the data unitcontained in the second program unit which will last for a time equal tothe time (TL1) when reproduced is identified by referring to the dataunit allocation table (DAT) (Step S16). Then, the data reproducingapparatus controls the pickup driving section 104, whereby the pickupmeans searches for the start address of the second data unit (Step S17).Then, the data reproducing apparatus decodes the second data unit, fromthe first frame thereof, but section 203 prohibits the output of videoinformation until the number of frames counted reaches the number (FNO)of the frames of the first program bar which are stored into the memory(Step S18).

The function illustrated in the flow chart of FIG. 12 may beincorporated in the data reproducing apparatus, either singly ortogether with the function represented in the flow chart of FIG. 11. Ifthe flow chart of FIG. 11 and that of FIG. 12 are incorporated in theapparatus and used as main flow and sub flow, respectively, the latterwill serve as an interruption routine, wherein Step S18 is followed byStep S11. Alternatively, the flow charts of FIGS. 11 and 12 may beincorporated into the apparatus such that they can be switched, from oneto the other. In this case the menu shown in FIG. 5C or FIG. 7 isdesirable. Namely, to allow the user to have a multi-scene with thepresent scene covered as little as possible. It is preferable to displaythe menu screen of FIG. 5C. When the user knows before the reproductionof the disk that there is a program containing a multi-scene and hasdecided to use the program, a multi-scene screen as shown in FIG. 7 ispreferable. If the menu of FIG. 5C the choice, it should better bedisplayed in a step between Steps S13 and S14 in FIG. 12.

In Step S18 (FIG. 12), the output of video information may be initiatedin an following alternative way, which will be explained below.

FIG. 13 is a diagram illustrating the timing of giving a command to thesystem control section in order to switch the program bars (FIG. 3A)representing simultaneously proceeding scenes, for example, from theprogram bar #4 to the program bar #5. Assume that the command is inputthe moment the fifth frame of the nth-second data unit (DUT) containedin the program bar #4. Then, the data reproducing apparatus startsoutputting video information, frame by frame, from the fifth frame ofthe nth-second data unit of the program bar #5 if the apparatus performsthe sequence of steps shown in FIG. 12. In other words, the apparatusstarts outputting the video information counting the fifth of thepulses, each generated upon completion of a frame. When the apparatusstarts outputting the video information, the nth-second data units ofthe program bars #4 and #5 have the positional relationship indicated bybroken line 951. Alternatively, the apparatus may start outputting videoinformation when the first frame of the nth-second data unit of theprogram bar #5 is decoded in its entirety, as is illustrated by brokenline 952. Still alternatively, the apparatus may start outputting videoinformation at the time the first frame of the (n+1)th-second data unitof the program bar #5 is decoded in its entirety, as is illustrated bybroken line 953.

If time is available before the apparatus starts outputting the videoinformation contained in the program bar #5, the last frame of the videoinformation contained in the program bar #4, which has been alreadyoutput, is written into the image memory incorporated in the decoder orthe system control section 204. The last frame is repeatedly read fromthe image memory, whereby the scene represented by the last frame thevideo information is displayed on the monitor in the form of a stillpicture.

Assume that the nth-second data unit in the program bar #4 and thenth-second data unit in the program bar #5 represent two images of thesame actor uttering words, which have been photographed by two camerasand, thus, at different angles. In this case, the program bars #4 and #5are identical in terms of audio information. Hence, the audioinformation (AUDIO shown in FIG. 2B) contained in the nth-second dataunit in the program bar #4 can be used while the nth-second data unit inthe program bar #5 is being reproduced from the disk.

FIG. 14 is a timing chart for explaining a method of outputting audio orvideo information more easily after program bars representingsimultaneously proceeding scenes have been switched, from one toanother. In this method, a buffer memory is used to temporarily storethe audio or video information read from the disk.

Illustrated in FIG. 14 are the nth-second data unit #4U in the programbar #4 shown in FIG. 13 and the nth-second data unit #5U in the programbar #5 shown in FIG. 13. Also shown in FIG. 14 are: the period A4 duringwhich audio information #4A is read from the disk; the period A5 duringwhich audio information #5A is read from the disk; the period V4 duringwhich video information #V4 is read from the disk; and period V5 duringwhich video information #5V is read from the disk. Further, shown inFIG. 14 are: the period AV4 during which the audio information A4 andthe video information V4 are output from the data reproducing apparatus;and the period AV5 during which the audio information A5 and the videoinformation V5 are output from the data reproducing apparatus. Thebuffer memory used to facilitate the outputting of audio information andvideo information has a storage capacity large enough to store at leastthe data unit #4U and the data unit #5U. Thus, the data unit #5U can bedecoded after the data unit #4U has been decoded in its entirety. Theaudio information and the video information can thereby be reproducedwithout break, even if the program bars representing simultaneouslyproceeding scenes are switched, from one to another. If the data units#4U and #SU are part of a movie program, audio information itemscontained in these data units are preferably recorded so as to bereproduced without a time lag. In the above explanation, the timerequired to move the pickup is not taken into consideration.

As has been described with reference to FIG. 10, the disk may contain aparental consent code if the movie program recorded on that diskcontains program bars representing simultaneously proceeding scenes, atleast one of which should not be displayed to children.

The operation of the parental consent code will now be explained withreference to the flow chart of FIG. 15. First, when the disk is placedon a turntable and rotated, the management data (i.e., VID, PIF and DAT)is read from the management area of the disk and subsequently storedinto the work memory. Next, the data reproducing apparatus determineswhether or not the management data contains a parental consent program(Steps S25 and S26). The step of determining this may be performed invarious methods. One method is to detect the presence or absence ofparental consent data in the sub-code of a data unit, either immediatelyafter the disk has been placed on the turntable or while the data unitis being reproduced from the disk. Another method is to detect thepresence or absence of a flag in the VID (see FIG. 8A), which has beenset for a particular program movement (i.e., a story).

In the case of FIG. 15, it is first determined whether or not a parentalconsent program has been recorded (Steps S21 to 23). If the managementdata contains no parental consent program, the program bars arereproduced from the disk in accordance with the standard program link(Step S24). If the management data contains a parental consent program,a menu of the type shown in FIG. 10B is displayed (Step S25). If thesecret code known only to adult users has been input, the program barsare reproduced from the disk in accordance with a specified program link(Step S27).

An alternative operation of the parental consent code will now beexplained with reference to the flow chart of FIG. 16. In FIG. 16, thesteps identical to some of the steps illustrated in FIG. 15 aredesignated by the identical symbols. when there is no parental consentprogram, control goes to Step S32, in which a program select menu screenis displayed. When a parental consent program is present, a commentscreen is displayed, and it is determined whether or not a secret codekey has been pressed (Steps S25 and S26). If the secret code key has notbeen pressed, control proceeds to Step S32, in which a program selectmenu screen is displayed. If the secret code key has been pressed, theparental consent mode is canceled (Step S31) and control goes to StepS32. When the user has selected a program, a data string, or a storyunder the program select menu screen, a reproducing operation isperformed according to the selection. When the parental consent mode hasbeen canceled, for example, an image display process is achieved in anormal state without effecting the image display process showing in FIG.10A.

When reproduced data strings of any program are controlled, theextension tables described above with reference to FIGS. 9B-9D andrecorded as management data are useful.

FIG. 17 is a flow chart explaining how a monitor displays allsimultaneously proceeding scenes recorded on the disk, one afteranother. First, the data is is read from the disk (Step S41). Then, asub-code is read from the disk (Step S42). The sub-code contains a code(e.g., a parental consent code) which indicates the program informationconcerning program bars representing simultaneously proceeding scenes.Upon detecting this code, it is determined whether or the user has set adivided-frame display mode by operating the operator panel (Step S43).

If the divided-frame display mode has been set, existing linked programbars, are displayed (Step S44). FIG. 18A shows a divided-frame menuwhich is displayed when four program bars #11, #12, #13 and #14 arelinked to one another. FIG. 18B shows a divided-frame menu, displayingthe program bars #11, #12, #13 and #14 in the form of 1/4-sized bars#11', #12', #13' and #14'. In Step S44, the program bar #15 isreproduced, thereby displaying 1/4-sized bars #11', #12', #13' and #14'.

If the divided-frame display mode is found not to have been set has beenset in Step S43, the scene switching data is read from the disk (StepS45). Then, it is determined whether or not the scene switching datarepresents a scene enlarging mode (Step S46). If the scene switchingdata does not represent a scene enlarging mode, the flow goes to StepS44, in which multi-scene display is performed. If the scene switchingdata represents a scene enlarging mode, data for selecting a scene to bedisplayed in an enlarged form (e.g., data-string selecting data or storyselecting data) is read from the disk, and the program bar representingthe selected scene is reproduced from the disk, whereby the scene isdisplayed on the monitor in an enlarged form (Steps S48). When a diskcontains a program as shown in FIG. 18B a screen as shown in FIG. 18Aappears when control has been passed from Step S43 or step S46 to step44; Namely, the program bars #10, #15, #10, #16, . . . are reproduced inthat order. When an enlarged screen has been specified, the reproductionof program bar #10 is followed by the reproduction of any one of #11,#12, #13, and #14 in a normal size. This is then followed by thereproduction of program bar #16.

In the embodiment described above, the program bar #15 has been recordedon the disk. Instead, to perform multi-scene display, the typical framesof the program bars #11, #12, #13 and #14, which representsimultaneously proceeding scenes, may be decoded, to form stillpictures. These still pictures may be displayed on the monitor until itis determined that the scene switching data represents a scene enlargingmode. In this instance, the data reproducing apparatus needs to haveadditional video processing sections including decoders, and a circuitfor processing the outputs from the decoders into reduced multi-scenevideo signals.

As has been described with reference to FIG. 2, recorded on the disk isa movie program which includes a plurality of data units, eachcontaining a plurality of audio information items representing speech invarious languages among other things. Therefore, the user can select oneof the audio information strings or one of the video informationstrings. Thus, the data string processing section 203 (FIG. 1) canselect an audio information item representing speech or a subtitle in aspecific language.

If selection mode is set in the data reproducing apparatus, a decoderstarts decoding the audio information in a data unit to be reproducedautomatically when one scene is switched to another. The languageselected at this time is identical to that used in the previouslydisplayed scene.

In the embodiment described above, the parental consent code is obtainedfrom the management data or a sub-code recorded on the disk. Theparental consent code is used; to V set the data reproducing apparatusin the parental consent mode. The parental consent mode is cancelled ashas been explained with reference to FIG. 16. In some case, however, theuser may wish to set parental consent codes to all or some of the moviestories recorded on a disk he or she has bought.

FIG. 19 is a flow chart for explaining how the data recording apparatusoperates when set in parental consent mode. First, the disk is placed onthe turn-table and rotated, and the management data is read (Steps S51and S52). Then, it is determined whether or not the user has operatedthe operator panel by inputting a request for a parental consent code(Step S53). If no request has been input, the data reproducing apparatusis set into normal reproduction mode. If a request has been input, amenu is displayed based on a program link table (Step S54). This menushows, for example, the ID numbers of information strings such one as isillustrated in FIG. 7, for example. Next, the user looks at the the menuand operates the operator panel, thus inputting the ID number of theinformation string he or she has selected (Step S55). Then, such a menuas shown in FIG. 10B is displayed on the monitor, advising the user toinput a parental consent code (Step S56). If the user inputs theparental consent code, the parental consent code, the the ID number ofthe selected information string, and the ID number of the disk, and thelike are stored into the work memory in the form of a set of data.

As described above, while set in the parental consent mode, the datareproducing apparatus not only reads the management data from the diskwhen the disk is placed on the turntable, but also reads data from thework memory. Thereafter, the operation goes to Step S23 shown in FIGS.15 and 16.

If the user has learned that the disk stores program bars representingsimultaneously proceeding scenes, he or may switch scenes at any time heshe want to. If the scene is not switched to the desired sceneinstantaneously, the user is likely to assume that the data reproducingapparatus has gone out of order, and that the appropriate one ofsimultaneously proceeding scenes may not be being reproduced. Havingbecome rather restless, the user is likely to operate the panelrepeatedly. To alleviate such anxiety the messages shown in FIG. 20 maybe displayed on the monitor screen.

For instance the moment the user operates the panel to switch the scenesrepresented by program bars linked in accordance with link information(for example, those program bars shown in FIG. 3B) the monitor displaysthe message shown in FIG. 20A, "IT IS NOT THE TIME TO SWITCH SCENES."Alternatively, the moment the user operates the panel to switchsimultaneously proceeding scenes from one to another, the monitordisplays the message of FIG. 20B, "THE PROGRAM BAR BEING REPRODUCED IS#1" or the message of FIG. 20C, "THE PROGRAM BAR BEING REPRODUCED IS#4." Seeing such a message on the monitor screen, the user need not beirritated at all.

FIG. 21A illustrates another multi-scene program. The multi-sceneprogram shown in FIG. 3B, for example, may be recorded in such a manneras illustrated in FIG. 21A. Namely, program bars #0, #1, #2, #1, #2, #1,#2, #3, #4, #5, #6, #4, #5, #6, #4, #5, #6, and #7 are arranged in thissequence. In other words, the program bar #0 is followed by program bars#1 and #2. On this disk, the program bars #1 and #2 are recorded in areaTA. The program bars #4, #5 and #6 which follow the program bar #3 andwhich represent simultaneously proceeding scenes are recorded in asimilar manner. In this case, the program bars representingsimultaneously proceeding scenes are less in data amount than thoseshown in FIG. 3B. The disk 100 of this record format is accessed by adata reproducing apparatus of the type shown in FIG. 21B. This datareproducing apparatus is almost the same as the apparatus shown in FIG.1, but differs in that the data string processing section 203incorporates a buffer memory 230. The buffer memory 230 is provided forstoring program bars which represent simultaneously proceeding scenes.For example, the data unit of program bars #1 and #2 are read andsubsequently stored into the buffer memory 230 after program bar #0.Similarly, the data unit of program bars #4, #5 and #6 are read andsubsequently stored into the buffer memory 230 after program bar #3. Theprogram bars representing simultaneously proceeding scenes are sent tothe video processing section 206. As a result, the monitor displays thescenes represented by these program bars at the same time, and generatessounds for these scenes. That is, multi-scene reproduction is achievedin real time. The program bars representing simultaneously proceedingscenes must be read from the disk at high speed. To this end, the systemcontrol section 204 drives the motor 102 at high speed. If n programbars are recorded on the disk representing n simultaneously proceedingscenes, then the motor 102 is driven at a speed n times higher. Sincethe program is recorded in the format shown in FIG. 21A, the pickupmeans need not be moved back and forth in the radial direction of thedisk.

FIGS. 22A and 22B show another example of an arrangement of program barswhich are recorded on a disk and which represent simultaneouslyproceeding scenes. In the case of this disk, four-scene information isrecorded when the program bar #11 following the program bar #10 isreproduced. Four scenes A to D are illustrated in these figures. On thescreen, the four scenes are simultaneously displayed in the form ofmoving pictures. Hence, the user can enjoy seeing the four scenes at thesame time. While the multi-scene display is being performed, the usercan select any one of the four scenes. When one of the four scenes isselected, it will be displayed in an enlarged size. FIG. 22B is a flowchart for explaining the software which is loaded in the datareproducing apparatus and which is designed to reproduce informationfrom the disk. First, the data reproducing apparatus starts normalreproduction. If a multi-scene part is detected during the normalreproduction, a simultaneously proceeding scene is reproduced to bedisplayed on a part of the screen. That is, the program bar #11 shown inFIG. 22A is reproduced (Steps S71 to S74). If the user selects one ofthe simultaneously proceeding scenes being displayed, the datareproducing apparatus converts the selected program bar representing theselected scene, to data which represents an enlarged scene. The selectedscene is thereby displayed in an enlarged form. Upon completion of thereproduction of the multi-scene part, the apparatus will resume thenormal reproduction (Steps S75 to S77).

Industrial Applicability

As has been described, the present invention can provide a multi-scenerecording medium on which images are recorded together with speech andsubtitle in various languages and which can therefore be usedworld-wide, and also a data reproducing apparatus which can reproducedata in various manners to meet various needs.

We claim:
 1. An apparatus for reproducing information from a multi-scenerecording medium including a disk having a management area and a dataarea, said data area recording a first program information item, asecond program information item following said first program informationitem, a third program information item following said second programinformation item, and a fourth program information item for replacingsaid second program information item, wherein said second and fourthprogram information items include simultaneously proceeding scenes, saidmanagement area recording multi-scene configuration informationindicating that second and fourth program information items are linkedto each other, data units of said second program information item anddata units of said fourth program information item being alternatinglyand continuously recorded on said recording medium, said apparatuscomprising:pickup means for generating signals based on informationrecorded on said disk; demodulation means for generating multi-sceneconfiguration data by demodulating signals generated by said pickupmeans, said multi-scene configuration data being based on saidmulti-scene configuration information recorded in said management areaof said disk; management data storage means for storing said multi-sceneconfiguration data generated by said demodulation means; menu generatingmeans for generating, based on a decoded output, a menu displaying animage relating to said program information item being decoded when saidmulti-scene configuration data indicates that said second or fourthprogram information item is being reproduced, said menu being used toswitch between reproduction of said second program information item andsaid fourth program information item, where when reproduction is to beswitched from one of the second and fourth program information items toanother of the second and fourth program information items while the oneprogram information item is being reproduced, reproduction of the otherprogram information item starts from a head portion of a data unit ofthe other program information item.
 2. A method of reproducinginformation from a multi-scene recording medium including a disk havinga management area and a data area, said data area recording a firstprogram information item, a second program information item followingsaid first program information item, a third program information itemfollowing said second program information item, and a fourth programinformation item for replacing said second program information item,wherein said second and fourth program information items includesimultaneously proceeding scenes, said management area recordingmulti-scene configuration information indicating that said second andfourth program information items are linked to each other, data units ofsaid second program information item and data units of said fourthprogram information item being alternatingly and continuously recordedon said recording medium, said method comprising the steps of:readinginformation from said disk and generating pickup signals based on saidinformation; generating multi-scene configuration data by demodulatingsaid pickup signals; storing said multi-scene configuration data; andgenerating a menu by combining an image corresponding to a programinformation item which is being reproduced with a decoded output of saidprogram information item which is being reproduced, when saidmulti-scene configuration data indicates that said second or fourthprogram information item is being reproduced, said menu being used toswitch between reproduction of said second program information item andsaid fourth program information item, where when reproduction is to beswitched from one of the second and fourth program information items toanother of the second and fourth program information items while the oneprogram information item is being reproduced, reproduction of the otherprogram information item starts from a head portion of a data unit ofthe other program information item.
 3. An apparatus for reproducinginformation from a multi-scene recording medium including a disk havinga management area and a data area, said data area recording a firstprogram information item, a second program information item followingsaid first program information item, a third program information itemfollowing said second program information item, and a fourth programinformation item for replacing said second program information item,wherein said second and fourth program information items includesimultaneously proceeding scenes, said management area recordingmulti-scene configuration information indicating that second and fourthprogram information items are linked to each other, data units of saidsecond program information item and data units of said fourth programinformation item being alternatingly and continuously recorded on saidrecording medium, said apparatus comprising:pickup means for generatingsignals based on information recorded on said disk; demodulation meansfor generating multi-scene configuration data by demodulating signalsgenerated by said pickup means, said multi-scene configuration databeing based on said multi-scene configuration information recorded insaid management area of said disk; management data storage means forstoring said multi-scene configuration data generated by saiddemodulation means; menu generating means for generating, based on adecoded output, a menu displaying an image relating to said programinformation item being decoded when said multi-scene configuration dataindicates that said second or fourth program information item is beingreproduced, said menu being used to switch between reproduction of saidsecond program information item and said fourth program informationitem, where when reproduction is to be switched from one of the secondand fourth program information items to another of the second and fourthprogram information items while the one program information item isbeing produced, reproduction of the other program information itemstarts from a head portion of a data unit of a program information itemnext to the other program information item.
 4. A method of reproducinginformation from a multi-scene recording medium including a disk havinga management area and a data area, said data area recording a firstprogram information item, a second program information item followingsaid first program information item, a third program information itemfollowing said second program information item, and a fourth programinformation item for replacing said second program information item,wherein said second and fourth program information items includesimultaneously proceeding scenes, said management area recordingmulti-scene configuration information indicating that said second andfourth program information items are linked to each other, data units ofsaid second program information item and data units of said fourthprogram information item being alternatingly and continuously recordedon said recording medium, said method comprising the steps of:readinginformation from said disk and generating pickup signals based on saidinformation; generating multi-scene configuration data by demodulatingsaid pickup signals; storing said multi-scene configuration data; andgenerating a menu by combining an image corresponding to a programinformation item which is being reproduced with a decoded output of saidprogram information item which is being reproduced, when saidmulti-scene configuration data indicates that said second or fourthprogram information item is being reproduced, said menu being used toswitch between reproduction of said second program information item andsaid fourth program information item, where when reproduction is to beswitched from one of the second and fourth program information items toanother of the second and fourth program information items while the oneprogram information item is being reproduced, reproduction of the otherprogram information item starts from a head portion of a data unit of aprogram information item next to the other program information item. 5.The apparatus according to claim 1, wherein each of said first, second,third and fourth program information items includes video data.
 6. Themethod according to claim 2, wherein each of said first, second, thirdand fourth program information items includes video data.
 7. Theapparatus according to claim 3, wherein each of said first, second,third and fourth program information items includes video data.
 8. Themethod according to claim 4, wherein each of said first, second, thirdand fourth program information items includes video data.